On 7 February 1992, Spain and Britain were among the 12 members of the European Community to sign the Treaty on European Union, informally known as the Maastricht Treaty after the Dutch city in which this took place. The other EC members at the time were Belgium, Denmark, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands and Portugal.
Each country then ratified the Treaty, in the case of France, Ireland and Denmark after holding referenda, and it officially came into force on 1 November 1993. The European Union was born.
The Maastricht Treaty took several years to draw up and it had far-reaching effects. It established European citizenship for the first time, and meant citizens of member states were able to live and move freely between them.
A common foreign and security policy was agreed, together with closer cooperation between police and justice systems in criminal matters. It also laid the foundations for the single currency, the euro, and established the European Central Bank and the European System of Central Banks.
Thanks to Maastricht, citizens of EU states were given the right to vote and stand as a candidate in European and local elections in the country in which they lived; eligibility for diplomatic assistance and protection from the embassies and consulates of other member countries; the right to petition the European Parliament and take complaints of EU administrative malpractice to the European Ombudsman.
The aims of Maastricht were also to preserve peace and international security in line with United Nations' principles, promote international cooperation, develop and consolidate democracy and the rule of law, and respect for human rights and fundamental freedoms.
The Treaty also included protocols which enabled some countries to opt-out of some of the terms, such as the UK and Denmark having an option on whether to join the single currency and, if so, when to do so.
Another 16 countries joined the EU after Maastricht, bringing the total to 28, but as everybody must know, Britain decided to leave following a referendum in 2016, and is currently in a transition period following its official withdrawal a week ago.